Gas generators have been used for inflation of air bag restraint systems for some time. Those systems which are currently being used employ metal azide-based gas generators to produce the gas for inflating the air bag. The resulting gas generated by these azide based compositions is not suitable as a life sustaining gas. It lacks sufficient oxygen. Such gas generators are suitable for those gas bags used in the drivers side and passenger side air bags in conventional automobiles as the air contained in the passenger compartment is sufficient to dilute the gas products generated by a factor of about four to one or greater. Thereby minimizing the negative impact such gas might have on the occupants when the gas is released into the compartment. Typically, the resulting oxygen in the compartment will be reduced to between 16% to about 18% by volume. This is still suitable for sustaining life but well below the standard concentration of oxygen in air, which is about 21% by volume.
Another problem with the metal azide-based gas generators is the toxicity of these materials which has been a major deterrent to consideration in this type of inflation system for continued use for automobiles and for future use in aircraft.
Various attempts have been made to define an alternative gas generator that does not employ metal azides and yet produces a non-toxic gas mixture. In effect, none have been developed which produce a gas that will sustain life over a protracted period. Many of the suggested alternative generators produce appreciable carbon dioxide, carbon monoxide or unburned hydrocarbons, with and without the simultaneous formation of oxygen, making them unsuitable for breathing.
Therefore, what is needed in this art is a gas generator using non-hazardous components, yet is capable of meeting the requirements for inflating air bag restraint systems while producing a non-toxic, life-sustaining gas.